<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>复合选择器-伪类选择器 </title>
    <style>
         a:hover {
            color: red;
         }
         .box:hover{
            color: green;
         }
    </style>
</head>
<body>
    <a href="#"> a 标签</a>
    <div class="box"> div 标签</div>
</body>
</html>